Heat pumps are well known in the art and can be defined as any device that provides heat energy from a source of heat to a destination called a “heat sink”. Heat pumps are designed to move thermal energy opposite to the direction of spontaneous heat flow by absorbing heat from a cold space and releasing it to a warmer one. A heat pump uses some amount of external power to accomplish the work of transferring energy from the heat source to the heat sink. By definition, all heat sources for a heat pump must be colder in temperature than the space to be heated. Most commonly, heat pumps draw heat from the air (outside or inside air) or from the ground.
It is known to use heat pumps as a source of heat for heating an air space such as within a building or as a source of heating for domestic hot water. Typically a single heat pump will be connected to a single source and then the output from that heat pump is selectively used to transfers heat to air inside a building or transfer heat to a heating circuit and a tank of domestic hot water.
Known applications of heat pumps include their use in district heating. District heating is a system for distributing heat generated in a centralized location for residential and commercial heating requirements such as space heating and water heating. The heat is often obtained from a cogeneration plant burning fossil fuels but increasingly also biomass, although heat-only boiler stations, geothermal heating, heat pumps and central solar heating are also used, as well as nuclear power. District heating plants can provide higher efficiencies and better pollution control than localized boilers. Despite these advantages, there continues to exist a need for improvement in district heating architectures.
Furthermore, typically heat pumps are coupled to a single heat source—i.e. they are dedicated for use with one type of environment, be that an air source heat pump, a ground source etc. The efficiency of these heat pumps is predicated on the environment on which they are based being useable as a source of energy at the time when the heat pump operation is required.